Ratchet wrench



W. B. FORD RATCHET WRENCH 2 Sheets-Sheet l Filed May 25, 1953 mt., 4v 4W B. FORD RATCHET WRENCH Filed May 25, 1953 2 Sheets-Smet 2 UnitedStates Patent O RATCHET WRENCH William B. Ford, Bryan, Ohio, assignor toAro Equip-s This invention relates to a ratchet wrench of the openendtype which has a head that may be used on a hexagonshaped nut, a bolt, acap screw head, or a tubing nut, which is accessible only from the side,to impart rotation thereto either continuously or intermittently in aslittle as one-twelfth of a revolution, or by swinging motion of the toolto tighten through an are of from near zero to the index of the head(one-twelfth of a revolution), employing for this purpose a pair ofnut-engaging cams or rockers wherein notches in the sides of the camsengage the nut when the head is oscillated slightly more thanone-twelfth revolution.

This invention embodies certain improvements and changes over theratchet wrench disclosed by my prior application Serial No. 334,539,filed February 2, 1953.

' One object of the invention is to provide an open-end ratchet wrenchof this general character which may be power operated and which has arelatively small thickness so that it eliminates the necessity ofconsiderable head room to work on a nut or bolt as required by manytypes of power wrenches.

Another object is to provide a wrench which is adapted for poweroperation as by means of a pneumatic motor, the wrench comprising awrench head which is oscillatably mounted in a frame attached to themotor and the frame including mechanism for translating the rotations ofthe motor shaft into oscillations of the wrench head.

A further object is to provide a n'ovel wrench head which may be slippededgewise over a nut and when in operating position has a circular partclearing the corners of the nut, the circumferential extent of which isa greater than 180 degrees so that it substantially confines the nutagainst slipping of the wrench therefrom during operation of the wrench.

Still a further object is to provide a C-shaped wrench head which isoscillatably mounted in a frame of the tool and is provided with one ormore nut-engaging cams or rockers having notches therein to engage thenut and to rotate it when the wrench head is oscillated in onedirection, the cams being rotatable in the wrench head from a xedposition to a rotated position of compression against retaining springmeans, so that the notch surface of the cams rotates from a position ofengagement with the nut to one of clearance in ratcheting fashion whenthe wrench head is oscillated.

An additional object is to provide a relatively simple C-shaped wrenchhead with relatively simple cam and rocker arrangements in conjunctiontherewith, and a gear sector, idler gear, and rack arrangement forchanging reciprocations of the rack into oscillations of the wrenchhead, the rack in turn being reciprocated by a cam on the motor shaft.

Another additional object is to provide a holding pawl, having aserrated surface with a radius of curvature slightly larger than theouter radius of the nut head so as to clear the nut corners, the nutbeing centered by the cams when turned and held thereby just clear ofthe serrations, the holding pawl serving as a stop against the ICC nuthead during some types of operations and as a holding means to preventreverse rotation of the nut during other types of operations.

With these and other objects in view, my invention consists in theconstruction, arrangement, and combination of the various parts of myratchet wrench, whereby the objects contemplated are attained, ashereinafter more fully set forth, pointed out in my claims andillustrated in the accompanying drawings, wherein:

Figure l is a plan view of a ratchet wrench embodying my presentinvention with a cover plate removed and part of the housing and otherelements shown in section.

Figure 2 is a detail sectional view on the line 2-2 of Figure 1.

Figure 3 is a detail sectional view on the line 3--3 of Figure 1, andshows the motor for the wrench partially in side elevation.

Figure 4 is an enlarged view similar to the left-hand end of Figure l,with the wrench head shown in section, and illustrating the cooperationof one notched cam in each of two pair thereof with two opposite cornersof a nut.

Figure 5 is a similar view showing the nut turned 30 degrees clockwise.

Figure 6 is a similar View showing the wrench head being oscillated inthe opposite direction, and the notched cams ratcheting over the cornersof the nut.

Figure 7 shows the nal position for each of the other notched cams toengage the corners of the nut just before another reciprocationclockwise to rotate the nut another 30 degrees.

Figure 8 is a perspective view of a notched cam and its spring andkeeper pin as used in the wrench head of my ratchet wrench.

On the accompanying drawings I have used the referenee numeral 10 toindicate a motor for operating the wrench which motor may bepneumatically powered and provided with a throttle valve 12 and athrottle lever 14 in the usual manner. The shaft of the motor isindicated at 16.

I provide a body or frame 18 which is partially fiat and partiallycircular as shown in Figure 3. The circular part is engaged with a ange20 of the motor 10 by a retainer nut 22 so that the frame may be readilyconnected and disconnected in relation to the motor. `The frame 18 isprovided with a hollow space therein for an idler gear 24 having teeth2S, a rack 26 having teeth 27, and portions of a Gashaped wrench head2S. A stud 29 having reduced ends is provided on which the gear 24rotates.

The wrench head 28, as shown in Figure l, is provided with acircumference and an inner cylindrical surface 32. The circumference 30has a projection 34 as shown in Figure 2 which interts in acorresponding arc-shaped groove 33 of the frame 18 for permittingrotation or oscillation of the wrench head relative thereto. A coverplate 36 retains the wrench head in position and also covers the cavityin the frame in which the elements 24 and 26 are mounted. The projection34 of the wrench head is provided with gear teeth meshing with the idlergear 24, and the teeth of the idler gear 24 also mesh with those of therack 26 so that any oscillations imparted to the rack will oscillate thewrench head. For imparting such oscillations thereto, I provide a cam 38keyed at 4l) to a sleeve 42 mounted on the motor shaft 16 andcooperating with a roller 44 carried by the rack. To retain the rollerin contact with the cam 3S, I provide a spring 46 interposed between asocket 48 in the frame 18 and a socket 50 in a head 52 of the journalpin 54 provided for the roller 44, all as shown in Figure l.

With specific reference to the @shaped wrench head 28, it is providedwith opposite parallel jaws 56 and 58. The distance between these jawsis just slightly greater than the smal-l diameter of a hexagon nut 59 asshown in Figure 7. The cylindrical surface 32 is just large enough toreceive the nut or has a radius substantially equal to the radius of thecorner of the nut.

I` provide two pair of notched cams, 60 and 60a, and 61 and' 61a, whichare rotatably mounted in sockets 62, in the wrench head 28 along axesparallel to the longitudinal axis of the nut. The sockets are exposed atthe inner surface of the wrench head over an angle of arc substantiallyless than 180. The cams are retained in position by the wrench head 28,and are normally seated by means of springs 64 which bias keeper pins 65toward the cams, the keeper pins seating in recesses 66 in the cams asshown in Figure 8. Therefore, the notched cams or rockers can be forcedto rotate in their sockets against the bias of the springs 64 as shownin Figure 6, for instance (cams 60a and 61a), when the wrench head isoscillated in a return or counterclockwise direction.

Also in connection with the wrench head, I provide an L-shaped holdingpawl 68 having a serrated engagingsurface 69 with a radius of curvaturejust large enough to clear the` corners of the nut when the nut is heldin a centered position by the cams.

Practical operation In operation, my ratchet wrench may be placedagainst a bolt or cap screw head 59, as in Figure l, and the holdingpawl 68 is then forced against one or two corners of the nut, in whichposition the serrations. thereof act as a stop to prevent rotation ofthe nut in a direction opposite that desired. The notched cams orrockers, when they become operative to engage and rotate the nut, willserve to center the nut so as to provide clearance between the nutcorners and the holding pawl, whereupon actuation of the motor drivewill effect oscillation of the wrench head and rotation of the nutwithout interference therewith by the serrations of the pawl.

Assuming a starting position such as shown in Figure 4, the angle Abetween the notched cams 60 and 60a is substantially 30 degrees for myratchet wrench when designed for a hexagonal nut head in order to rotatethe nut in increments of one-twelfth of a revolution, as willhereinafter appear. It will be apparent that if the C- shaped wrenchhead 2.8 in Figure 4 is now rotated clockwise, the notched cams 60a and61a will have no effect, but the cams 60 and 61 will engage the upperand lower corners respectively of the nut 59 and rotate the nut in aclockwise direction through an arc of 30 degrees to a final position asshown in Figure 5, Whereupon the wrench head has reached the limit ofits clockwise rotation and is ready to rotate counterclockwise.

Figure 6 shows about one-half of the return or counter-clockwiserotation completed. The notched cams 60a and 61a' are now ratchetingacross the corners of the nut above referred to, and are shown rotatedin a counter-clockwise direction against the bias of springs 64. At thesame time, the serrations of the holding pawl will ac t to grip theadjacent corner of the nut as the manual pressure exerted by theoperator serves to move the wrench head forwardly against the nut'.Normally, the nut and wrench head will have some degree of free relativemovement, one within the other. When the gripping rockers areoperatively effective to turn the nut, the latter will be centeredwithin the head, permitting the corners of the nut to clear the serratedsurface of the holding pawl. As the rockers ratchet back across thecorner of the nut during a return oscillation, the manual force exertedby the operator will serve to eccentrically position the nut and head,relative to each other, thereby permitting the holding pawl to moveforwardly to engage and grip an adjacent corner of the nut and precludereverse rotation thereof. In this manner, counter-clockwise rotation ofthe nut as the rockers ratchet back is prevented.

Further rotation of the Wrench head will permit the springs 68 to returnthe cams 60a and 61a to the normal position of Figure 7 Where cams 60aand 61a now engage opposite corners of the nut for effecting the next 30degrees of rotation as the wrench rotates in` a clockwise direction.

Similarly, during the next counter-clockwise reciprocation of the wrenchhead, the cams 60 and 61 will ratchet over the next corners of the nutand assume the position of Figure 4 for rotating those corners. Thecycle will be repeated with the cam pairs 60-61 and 60a-61a alternatelyengaging the nut corners.

With a wrench of the character shown, the motor 10 may be used forrotating the nut 59 until it stalls the motor whereupon the length ofthe frame 18 plus the motor 10 serves as a handle of suflicient leverageto tighten the nut by hand, the gearing being locked due to coming tothe end of the throw such as the position shown in Figure l with theroller 44 at the bottom of the cam surface 38, or the wrench can be usedfor hand tightening at any position on the cam rise in confined areasfor small degrees of motion.

To rotate the nut in a counter-clockwise direction, it is merelynecessary to turn the complete wrench including the frame 18 over. Thewrench head can then be applied to the nut and the tool used as a handlever for loosening the nut after which the motor may be energized forremoving the nut. I have illustrated one size of wrench head 28 and itwill be obvious that it fits but one size of nut. It may, of course, bemade in various sizes and each Wrench, being readily attachable anddetachable relative to the motor 10, minimizes wrench changing. This isno disadvantage in mass production, however,` as it would be the usualpractice for one workman to operate. on only the size of nut which hiswrench will t.

Some changes may be made in the construction and arrangement of theparts of my ratchet wrench without departing from the real spirit andpurpose of my invention, and it is my intention to cover by my claimsany modified forms of structure or use of mechanical equivalents whichmay be reasonably included within their scope.

I claim as my invention:

l. In a ratchet wrench of the character described, a C-shaped wrenchhead, a frame oscillatably supporting said head, means for oscillatingsaid head relative to said frame, said head having opposite jaws ofsufficient spread to receive the small diameter of a nut, inwardly ofsaid jaws a surface of suticient size to receive the corners of the nutand of sufficient extent to substantially coniine the nut therein duringoscillations of said wrench head, two pairs of notched cams rotatablymounted in said head for engaging opposite corners of the nut, springmeans disposed in said head and biased toward said cams to hold the camsin a normally lixed position, said cams projecting through said inwardlydisposed surface of said head toward the nut to engage the cornersthereof and rotate it when said head is oscillated around the nut in onedirection, said cams rotating and ratcheting over the corners of the nutwhen said head is oscillated around the nut in the opposite direction,and a holding pawl having a serrated engaging surface with a radius ofcurvature slightly larger than the outer radius of'the nut head so as toclear the nut corners, the nut being centered by the cams when turnedand held thereby just clear of the serrations.

2. In a ratchet wrench of the character described, a C-shaped wrenchhead, a frame oscillatably supporting said head, means for oscillatingsaid head relative to said frame, said head having opposite jaws ofsucient spread to receive the small diameter of a nut, inwardly of saidjaws a surface of sufcient size to receive the corners of the nut and ofsufcient extent to substantially conne the nut therein duringoscillations of said wrench head, two pairs of notched cams rotatablymounted in said head for engaging opposite corners of the nut, springmeans disposed in said head and biased toward said cams to hold the camsin a normally fixed position, said cams projecting through said inwardlydisposed surface of said head toward the nut to engage the cornersthereof and rotate it when said head is oscillated around the nut in onedirection, said cams rotating and ratcheting over the corners of the nutwhen said head is oscillated around the nut in the opposite direction,and a holding pawl having a serrated engaging surface with a radius ofcurvature slightly larger than the outer radius of the nut head so as toclear the nut corners, the nut being centered by the cams when turnedand held thereby just clear of the serrations, said serrated engagingsurface having a circumferential extent greater than the angle subtendedby two adjacent nut corners.

3. In a ratchet wrench of the character described, a C-shaped wrenchhead, a frame oscillatably supporting said head, means for oscillatingsaid head relative to said frame, said head having opposite jaws ofsufficient spread to receive the small diameter of a nut, inwardly ofsaid jaws a surface of sufficient size to receive the corners of the nutand of sufficient extent to substantially confine the nut therein duringoscillations of said wrench head, two pairs of notched cams rotatablymounted in said head for engaging opposite corners of the nut, springmeans disposed in said head and biased toward said cams to hold the camsin a normally fixed position, whereby one of each of said pairs of camssimultaneously engages an opposite corner of the nut and effectsrotation of the nut when the head is oscillated in the one direction,each of the remaining cams of said pairs being then ineffective, each ofsaid first engaging cams ratcheting across the corners of the nut byrotation against their respective spring means when the head isoscillated in the other direction, and each of the other of said pairsof cams effectively engaging and ratcheting over the corners of the nutduring alternate cycles of oscillation.

4. In a ratchet Wrench of the character described, a C-shaped wrenchhead, a frame oscillatably supporting said head, means for oscillatingsaid head relative to said frame, said head having opposite jaws ofsufficient spread to receive the small diameter of a nut, a firstpartial cylindrical surface of sufficient size to receive the corners ofthe nut and a second partial cylindrical surface inwardly and of greaterradius of curvature than said first, the combined circumferential extentof said cylindrical surfaces being greater than 180 degrees tosubstantially confine the nut therein during oscillations of said wrenchhead, two pairs of notched cams rotatably mounted in said head forengaging opposite corners of the nut, spring means disposed in said headand biased toward said cams to hold the cams in a normally fixedposition, whereby one of each of said pairs of cams simultaneouslyengages an opposite corner of the nut and effects rotation of the nutwhen the head is oscillated in the one direction, each of the remainingcams of said pairs being then ineffective, each of said first engagingcams ratcheting across the corners of the nut by rotation against theirrespective spring means when the head is oscillated in the otherdirection, and each of the other of said pairs of cams effectivelyengaging and ratcheting over the corners of the nut during alternatecycles of oscillation.

5. In a ratchet wrench of the character described, a C-shaped wrenchhead, a frame oscillatably supporting said head, means for oscillatingsaid head relative to said frame, said head having opposite jaws ofsufficient spread to receive the small diameter of a nut, a firstpartial cylindrical surface of sufficient size to receive the corners ofthe nut and a second partial cylindrical surface inwardly and of greaterradius of curvature than said first, the combined circumferential extentof said cylindrical surfaces being greater than 180 degrees tosubstantially confine the nut therein during oscillations of said wrenchhead, two pairs of notched cams rotatably mounted in said head forengaging opposite corners of the nut, spring means disposed in said headand biased toward said cams to hold the cams in a normally fixedposition, said cams projecting through said first surface inwardlyltoward the nut to engage the corners vthereof and rotate it when saidhead is oscillated around the nut in one direction, and said cams beingrotated by the nut to expose the notched surfaces thereof in aratcheting fashion when said head is oscillated around the nut in theopposite direction.

6. In a ratchet wrench of the character described, a C-shaped wrenchhead, a frame oscilla'tably supporting said head, means for oscillatingsaid head relative to said frame, said head having opposite jaws ofsufficient spread to receive the small diameter of a nut, a firstpartial cylindrical surface of sufficient size to receive the corners ofthe nut and a second partial cylindrical surface inwardly and of greaterradius of curvature than said first, the combined circumferential extentof said. cylindrical surfaces being greater than degrees tosubstantially confine the nut therein during oscillations of said wrenchhead, two pairs of notched cams rotatably mounted in said head forengaging opposite corners of the nut, spring means disposed in said headand biased toward said cams to hold the cams in a normally fixedposition, said wrench head having cylindrical sockets for each of saidsaid cams, said sockets being exposed at said first partial cylindricalsurface, said cams projecting through said first surface inwardly towardthe nut to engage the corners thereof and rotate it when said head isoscillated around the nut in one direction, and said cams being rotatedby the nut to expose the notched surfaces thereof in a ratchetingfashion when said head is oscillated around the nut in the oppositedirection.

7. In a ratchet wrench of the character described, a C-shaped wrenchhead, a frame oscillatably supporting said head,` means for oscillatingsaid head relative to said frame, said head having opposite jaws ofsufficient spread to receive the small diameter of a nut, a firstpartial cylindrical surface of sufficient size to receive the corners ofthe nut and a second partial cylindrical surface inwardly and of greaterradius of curvature than said first, the combined circumferential extentof said cylindrical surfaces being greater than 180 degrees tosubstantially confine the nut therein during oscillations of said Wrenchhead, two pairs of notched cams rotatably mounted in said head forengaging opposite corners of the nut, spring means disposed in said headand biased toward said cams to hold the cams in a normally fixedposition, said wrench head having cylindrical sockets for each of saidcams, said sockets being exposed at said first partial cylindricalsurface over an angle of arc substantially less than 180 degrees so thatsaid cams are retained in position by portions of the head, said camsprojecting through said first surface inwardly toward the nut to engagethe corners thereof and rotate it when said head is oscillated aroundthe nut in one direction, and said cams being rotated by the nut toexpose the notched surfaces thereof in a ratcheting fashion when saidhead is oscillated around the nut in the opposite direction.

8. In a ratchet wrench of the character described, a C-shaped wrenchhead, a frame oscillatably supporting said head, means for oscillatingsaid head relative to said frame, said head having opposite jaws ofsufficient spread to receive the small diameter of a nut, a firstpartial cylindrical surface of sufficient size to receive the corners ofthe nut and a second partial cylindrical surface inwardly and of greaterradius of curvature than said first, the combined circumferential extentof said cylindrical surfaces being greater than 180 degrees tosubstantially confine the nut therein during oscillations of said wrenchhead, two pairs of notched cams rotatably mounted in said head alongaxes parallel to the longitudinal axis of the nut for engaging oppositecorners of the nut, said wrench head having cylindrical sockets for eachof said cams, said sockets being exposed at said first partialcylindrical surface over an angle of arc substantially less than 180degrees so that said cams are retained in position by portions of thehead, said cams projecting through `said iirst surface inwardly towardthe nut to engage the corners thereof and rotate it when said head is"oscillated around the nut, and spring means mounted in the head andbiased toward said cams to hold the cams in a normally fixed positionwith respect to rotation about the said axes.

9..,In a ratchet wrench of the character described, a llfshaped wrenchhead, a frame oscillatably supporting said head, means for oscillatingsaid head relative to said frame, said head having opposite jaws ofsufficient spread to receive the small diameter of a nut, inwardly ofsaid jaws a surface of suliicient size to receive the corners of the nutand of suficient extent to substantially cjon'fi'ne the nut thereinduring oscillations of said wrench head, two pairs of notched camsrotatably mounted in said head for engaging opposite corners of the nut,springrneans disposed in said head and biased toward said earns to holdthe cams in a normally fixed position, said cams projecting through saidinwardly disposed'surface of said head toward the nut to engage thecorners thereof and rotate it when said head is oscillated around thenut in one direction, said cams rotating and ratcheting over the cornersof the nut when said head is oscillated around the nut in the oppositedirection.

v 10. In a ratchet wrench of the charac-ter described, a C-shaped wrenchhead, a frame oscillatably supporting said head, means for oscillatingsaid head relative to said frame, said head having opposite jaws ofsufficient ,spread to receive the small diameter of a nut, Vinwardly CFIof said jaws a surface of sufficient size to receive the corners of thenut and of sufiicient extent to .substantially confine the nut thereinduring oscillations of said wrench head, two pairs of notched camsrotatably mounted'in said head for engaging opposite corners of the nut,spring means disposed in said head/and biased toward said cams to holdthe cams in a normally fixed position, said cams projecting through saidinwardly disposed surface of said head toward the nut to engage thecorners thereof, one of each of said pair of cams engaging diametricallyopposite corners of the nut and eflecting rotation of the nut when thehead is oscillated in the one direction and ratcheting across thecorners of the nut by rotation against their respective spring meanswhen the head is oscillated in the other direction, each of the other ofsaid pairs of cams eifectively engaging and ratcheting over the cornersof the nut during alternate cycles o'f'oscilla-4 tion.

References Cited in the iile of this patent UNITED STATES PATENTS Sharilv. a Dec. 20, 1949

